Pen



FIG. 1 is a perspective view of a pen showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The dashed broken lines in the drawing are for the purpose of illustrating unclaimed portions of the pen and form no part of the claimed design, and the dash-dot-dash broken lines illustrate the boundary of the claimed design. 

CLAIM The ornamental design for a pen, as shown and described. 